The invention relates to connecting assemblies at a driveshaft, i.e. between an outer joint part of a constant velocity joint of the driveshaft and a wheel hub, or between an outer joint part of a constant velocity joint of the driveshaft and a shaft flange, e.g. of a shaft journal of a differential drive, for the purpose of being used in the driveline of a motor vehicle.
U.S. Pat. No. 967,395 proposes a claw coupling between two rotating hollow shafts. The individual claws comprise internal grooves which, in the engaged condition, form a circumferential continuous groove which, on the inside, is engaged by a retaining ring. This type of coupling is not suitable for connecting annular parts with intermediate walls or inserts because it is necessary to provide access for fitting the retaining ring through the inside of the hollow shafts.
From DE 8136172 U1 there is known a coupling for rigidly connecting coaxial components in the case of driveshafts. The parts to be connected are each provided with end toothings which are inserted into one another. For axial securing purposes, the components to be connected are provided, behind the end toothing, with a shaft step with spring-back. In the inserted condition of the end toothings, circumferentially distributed U-profile pieces in the form of circular segments are inserted into said shaft steps. To prevent the U-profile pieces from becoming unfastened, they have to be joined to form a ring or they have to be secured by a ring slid over same or they have to be tensioned relative to one another by wedges. This leads to very complicated assembly procedures.
DE 196 45 880 A1 describes a connecting assembly between an outer joint part of a constant velocity joint and the shaft flange of a gearbox shaft wherein the two parts, for the purpose of transmitting torque, engage one another in a play-free way in the direction of rotation via inter-engaging claw toothings. At the outer joint part, the front ends of the claws form a composite planar end face which is supported on a composite planar end face at the shaft flange between the base regions of the claws. At each of the ends of the claws of the two parts, there are provided outwardly pointing catches which, at each of the parts, form a composite annular collar with a backwardly pointing conical inclined face. For axially tensioning in a play-free way the planar end faces of the two parts, which planar end faces contact one another, there is inserted a securing ring between the annular collars composed of said catches, which securing ring is positioned on the conical inclined faces. In addition to the inclined faces and the flank faces of the teeth of the claw toothings, the planar end faces have to be machined very accurately in order to form a play-free torque-transmitting connection.
It is the object of the invention to provide connecting assemblies between an outer joint part of a constant velocity joint of a driveshaft and a wheel hub, and between an outer joint part of a constant velocity joint of a driveshaft and a shaft flange, e.g. of a shaft journal of a differential drive, which connecting assemblies are lightweight and strong, easy to produce and quick to mount.
The objective is achieved in that the end toothing of an outer joint part of a constant velocity joint of the driveshaft, which outer joint part is at the wheel hub end, and the end toothing of a wheel hub are axially inserted into one another and circumferentially engage one another in a play-free way and that the teeth of the end toothings each comprise radially outwardly opening circumferential grooves which are delimited by two flanks and which, jointly, form a circumferentially extending annular groove in which, on the outside, there is arranged a securing ring; and in that the end toothing of an outer joint part of a constant velocity joint of the driveshaft, which outer joint part is at the shaft flange end, and the end toothing of a shaft flange are axially inserted into one another and circumferentially engage one another in a play-free way and that the teeth of the end toothings each comprise radially outwardly opening circumferential grooves which are delimited by two flanks and which, jointly, form a circumferentially extending annular groove in which, on the outside, there is arranged a securing ring.
The inventive connecting assemblies are advantageous in that they can be quickly and easily mounted. Because of the very short displacement distances when inserting the end toothings into one another, driveshafts can very easily be mounted between, and removed from between, the wheel hub and the shaft flange of a differential drive, especially in respect of the complete vehicle with a finish-assembled and finish-mounted wheel suspension system. This is advantageous for both the initial assembly and also for subsequent repair work. The connecting assembly is also characterised in that it requires only a small number of parts and features a low weight. The end toothings can be produced largely by a non-chip producing forming operation, with only the circumferential grooves having to be recessed into the teeth by a chip-forming operation, either on each part on its own or, in the case of inter-engaging end toothings, on both parts simultaneously.
Any torque which has to be transmitted by the driveshaft is accommodated by the inter-engaging end toothings of the connecting assembly. Any rotating bending moments at the connecting assembly which are generated by the constant velocity joint rotating in an articulated condition primarily act on the securing ring arranged in the annular groove, with one flank in each circumferential groove being loaded by the securing ring and with the other flank being unloaded; in the case of circumferential grooves which directly circumferentially adjoin one another and which are each associated with another tooth and thus with another one of the two sets of end toothing, the securing ring loads the respective flanks pointing in opposite directions.
According to a first advantageous embodiment it is proposed that, when viewed in cylindrical sections, the teeth of the two end toothings comprise flanks which extend parallel relative to the longitudinal axis of the parts, i.e. feature a simple geometry and, in consequence, are easy to produce.
Because of the axial displaceability of such end toothings, the securing ring and the circumferential grooves have to be designed in such a way that the former is supported by both flanks on the latter in a play-free way to be able to accommodate axial forces in both directions without there occurring any axial offset when the direction of load application changes.
According to a further advantageous embodiment it is proposed that, when viewed in cylindrical sections, the teeth of the two sets of end toothing comprise flanks which enclose an angle with the longitudinal axis of the parts, with the angles between the flanks of the teeth of the two sets of end toothing opening in opposite directions and being of identical size. The teeth of the two sets of end toothing are thus wedge-shaped and can be inserted into one another in a play-free way. The wide tooth bases ensure an increase in strength and uniform loads in the teeth.
With such end toothings with teeth which enclose an angle, axial support of the parts in one direction (pressure) is ensured so that the securing ring and the circumferential grooves can be designed in such a way that play-free contact between the securing ring and the flanks of the groove occurs in the opposite direction (tension) only. The circumferential grooves of the one set of end toothing can be displaced relative to the circumferential grooves of the other set of end toothing in such a way that there is formed a to-and fro-jumping annular groove. In consequence, the flanks of the securing ring contact only those flanks of the circumferential grooves which face the respective other set of end toothing.
A further advantageous embodiment comprises circumferential grooves of the two sets of end toothing which are provided with flanks extending parallel relative to one another, with the securing ring comprising corresponding flanks extending parallel relative to one another. Such circumferential grooves are easy to produce, and it is possible to use standard securing rings.
According to a further embodiment it is proposed that the flanks of the circumferential grooves of the two sets of end toothing enclose an angle relative to an imaginary axis-normal radial plane, which angle opens radially out-wardly, and that the securing ring is provided with corresponding flanks which enclose an identical angle relative to an imaginary axis-normal radial plane. In the inserted condition of the end toothings, the circumferential grooves thus form an annular groove which receives a securing ring with a wedge-shaped profile. Because the securing ring comprises a radial tensioning force, it is pressed into the annular groove, with axial force components occurring due to the wedge-shape of the securing ring.
In cooperation with wedge-shaped end toothings, the wedge-shape of the securing ring and of the circumferential grooves, which form a to-and-fro-jumping annular groove, can generate axial force components which, in the final analysis, press the two sets of end toothing further into one another. In this way, it is possible to avoid an axial play and a circumferential play in the connecting assembly.